The invention relates to a rectifier diode. It is known for medium- and higher-power rectifier diodes to be embodied as press-fit diodes. The press-fit diodes have a press-fit base, which is press-fitted into a corresponding recess in a rectifier arrangement. In this process the press-fit base at the same time accomplishes durable thermal and electrical connection of the rectifier diode to the rectifier arrangement. Such arrangements are known in automotive engineering, for instance, where they are used as rectifiers in the motor vehicle generators. The press-fit base there has a fastening region to which a semiconductor chip is secured, for instance by soldering. A so-called head wire is secured in turn on the semiconductor chip, again for instance by soldering, and it is then firmly connected electrically to a phase supply line of the motor vehicle generator, for instance by soldering or welding.
When the rectifier diode is press-fitted into an intended opening of a rectifier arrangement, mechanical forces engage the edge of the rectifier diode. These mechanical forces are transmitted via the press-fit base to the fastening region of the semiconductor chip. In the press-fitting operation, the semiconductor chip mounted on the fastening region undergoes bending stress. The solder layers between the semiconductor chip and the press-fit base and between the semiconductor chip and the head wire are also affected by the bending stress.
In German Patent Disclosure DE 41 12 286 A1, the press-fit base is made of solid metal, specifically in the form of a centrally disposed pedestal on which the semiconductor chip is mounted. This already provides spatial separation of the semiconductor chip from the edge of the press-fit base that is acted upon by the press-fitting forces. Despite the separation, the chip and the solder layers surrounding it undergo bending stress, which can lead to the immediate failure or later premature aging of the press-fit diode.
In an alternative construction of a rectifier diode without a pedestal or a bulwark surrounding such a pedestal, the sturdiness and reliability of the component depends on the chip's being secured in an exactly centered manner in production.